1. Field of the Invention
The present invention relates to a light-emitting device having a three-dimensional confinement resonator and a light source unit including the light-emitting device. More particularly, the invention relates to a light-emitting device having a three-dimensional confinement resonator which can be applied to light sources for a display device, an optical communication apparatus and an optical-disk.
2. Background Art
Photonic crystal is crystal obtained by artificially applying a refractive-index modulation structure to a substance at a period on the order of light wavelength and is able to control propagation of light in the crystal. A large number of phenomena have been reported so far with respect to such crystals. For example, a typical phenomenon shows that it is possible to prevent light having a certain frequency from propagating through a crystal by means of a photonic band gap (hereafter referred to as PBG).
There are many applied techniques for photonic crystal. Among them, confining light in a microspace by using the property of PBG to apply it to a new device has been energetically studied in recent years.
The photonic crystal can be divided into two dimensions and three dimensions depending on the difference of the property of PGB. Particularly, in the case of a three-dimensional photonic crystal, PBG is present in all orientations of space (complete PBG). Therefore, forming a microdefect in crystal makes it possible to completely confine light in the defect. Therefore, by using the defect as a resonator to provide a completely-confining resonator, it is expected that resonator loss can be greatly decreased and a laser device having a very low threshold can be realized.